| Project/Area Number |
12555208
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Metal making engineering
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
YOSHIDA Makoto Hiroshima University, Graduate School of Engineering, Research Associate, 大学院・工学研究科, 助手 (80277847)
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| Co-Investigator(Kenkyū-buntansha) |
SASAKI Gen Hiroshima University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (30192595)
FUKUNAGA Hideharu KURE NATIONAL COLLEGE OF TECHNOLOGY, Director, 校長 (90034347)
石川 敏弘 宇部興産株式会社, 宇部研究所・機能材第1研究部, 部長
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥13,500,000 (Direct Cost: ¥13,500,000)
Fiscal Year 2002: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2001: ¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 2000: ¥7,100,000 (Direct Cost: ¥7,100,000)
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| Keywords | Composite / residual stress / Ceramics / acoustic emission (AE) / SiC / CMC / Fiber |
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| Research Abstract |
As a potential material for high temperature services, unidirectional SiC fiber reinforced SiO2-mullite composites were fabricated by slurry impregnation method and liquid phase hot-pressing. A sintered SiC fiber was selected as the reinforcement. The hot-pressing was performed in graphite dies at the conditions of 1923 K, 30 Mpa, 3.6 ks in vacuum. In order to investigate influence of thermal residual stress on the mechanical properties, three levels of matrix composition were selected, I.e., SiO2- 3.7, 30, 50 mol. % Al2O3, to control thermo-elastic mismatch between fiber and matrix.
Three-point flexural test was carried out at 298 K and 1573 K. The ultimate strength was nearly 1 Gpa at each test temperature except for the SiO2- 3.7 mol.% Al2O3 matrix composite tested at 1573 K. Thus, the effect of thermal residual stress on the ultimate strength was not remarkable. Furthermore, the effect of the thermal residual stress on the proportional limit of the composites was investigated during three-point flexural test with acoustic emission CAE) monitoring at 298 K. The highest proportional limit was resulted from the highest compressive residual stress in the matrix of SiO2-3.7 mol.% Al2O3 composite. However, no apparent matrix cracking stress was detected by monitoring AE signals during three-point flexural test.
The SiO2- 3.7 mol.% Al2O3 matrix composite with large amount of SiO2 glass in the matrix caused plastic deformation of the test pieces at 1573 K. On the other hand, the network structure that the primary mullite crystal bonds each other in the SiO2- 30, 50 mol.% Al2O3 matrix composite was effective to prevent the plastic deformation of the matrices during the flexural test at 1573 K.
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